Transparent wallmounting leaflet/information/bills? or suchlike holders made of some kind of hard rigid 'plastic' and should make useful wall-mounted storage when properly wall-mounted. They don't seem to lie quite flat against the wall but they do have keyholes for screw mounting. (see photos) They also seem to be able to hook onto each other in some way but i haven't figured out exactly how.
About 8"high by just over 4" wide and 1" deep (not including mounting tabs.)
Rescued from a shop closing down but no longer needed.